Elevated intestinal fatty acid binding protein and gastrointestinal complications following cardiopulmonary bypass: a preliminary analysis

BACKGROUND

Cardiopulmonary bypass (CPB) is associated with poorly understood alterations in gastrointestinal (GI) perfusion. Intestinal fatty acid binding protein (IFABP), a cytosolic protein uniquely located in mature small-intestinal enterocytes, has been shown to be a sensitive biochemical marker of early intestinal ischemia when assayed in urine. We hypothesized that if significant small-intestinal ischemia occurs with CPB, then urine IFABP levels should be concomitantly elevated.

METHODS

Twenty-nine patients (15 low risk and 14 high risk) undergoing cardiac surgery with CPB were studied prospectively. Serial urine IFABP levels were measured and results were correlated with clinical outcomes.

RESULTS

None of the low-risk patients had IFABP elevations or experienced GI complications. Five of the high-risk patients had IFABP elevations, and three of the five developed GI complications. Within the high-risk cohort, the only significant difference between patients with or without IFABP elevations was the GI complication rate (P = 0.03). Overall, patients with IFABP elevations had a significantly higher mean ASA class and significant increases in mean CPB and aortic cross-clamp times, mean time to oral intake, median ICU and postoperative lengths of stay, and GI complications.

CONCLUSIONS

In low-risk bypass patients, small-bowel mucosal perfusion appeared to be maintained, while in the high-risk population, 21% of the patients sustained clinically significant mucosal compromise. In this pilot study, urine IFABP was 100% sensitive and 92% specific with respect to GI complications. Since elevated urine IFABP concentrations appeared to correlate with clinical GI complications, urine IFABP may be a useful marker to identify the patient at risk for postbypass GI complications.

Amphotericin B lipid complex for neonatal invasive candidiasis

This study describes the safety and efficacy of amphotericin B lipid complex (ABLC) in 11 neonates with systemic Candida infections. Nine of the 11 improved clinically, and eight of nine evaluable patients had a mycological cure with ABLC. Creatinine levels improved or did not significantly change in eight of the 11 patients.

Total warm ischemia and reperfusion impairs flow in all rat gut layers but increases leukocyte-vessel wall interactions in the submucosa only

OBJECTIVE

To study the effect of warm ischemia and reperfusion (I/R) on local perfusion and leukocyte-vessel wall interactions in vivo in all small bowel layers, and to quantify small bowel tissue injury histologically and by measuring intestinal fatty acid binding protein (I-FABP) release from the enterocytes.

SUMMARY BACKGROUND DATA

Gut injury as a result of I/R plays a pivotal role in a variety of clinical conditions, such as small bowel transplantation, heart or aortic surgery, and (septic) shock. The precise mechanism behind I/R injury and the role of microvascular changes remain unclear. The influence of warm I/R of the gut on microvascular parameters in the different gut layers has not been studied before.

METHODS

Anesthetized Lewis rats were either subjected to 30 minutes of ischemia and 1 hour of reperfusion or sham-treated as controls. After ligating the inferior mesenteric artery, total warm ischemia was induced by clamping the superior mesenteric artery. Intravital video microscopic measurements were obtained at intervals. Tissue injury of the small bowel and other organs was histologically evaluated afterward. In addition, plasma levels of I-FABP were determined to measure enterocyte damage.

RESULTS

After ischemia, mean red blood cell velocity decreased significantly in all layers of the small bowel, but no diameter changes were observed. Leukocyte-vessel wall interactions increased in the submucosa but not in the muscle layers. Plasma levels of I-FABP significantly increased from 30 minutes of reperfusion onward. The intestinal mucosa was severely injured; no histologic damage was detected in other tissues.

CONCLUSIONS

This is the first in vivo study showing that total warm ischemia of the rat gut impairs perfusion in the whole small bowel, whereas leukocyte-vessel wall interactions increase in the submucosal layer only. Therefore, the early inflammatory response to I/R seems to be limited to the submucosa. Both microvascular effects may have contributed to the severe morphologic and functional mucosal injury observed after I/R.

Plasma intestinal fatty acid binding protein in neonates with necrotizing enterocolitis: a pilot study

BACKGROUND/PURPOSE

Intestinal fatty acid-binding protein (IFABP) is found within cells at the tip of the intestinal villi, an area commonly injured when necrotizing enterocolitis (NEC) occurs. This study was undertaken to determine if measuring IFABP concentrations in the bloodstream early in the course of NEC would differentiate patients by severity before clinical findings made it clear who had stage 3 NEC and who had milder stages.

METHODS

Three plasma samples from newborn infants evaluated for NEC were obtained at symptom onset and after 8 and 24 hours. IFABP concentration was measured by radioimmunoassay. Infants were classified by the final and most severe stage of NEC, and IFABP levels were compared between groups at each sampling.

RESULTS

IFABP was detectable in blood samples from all 7 infants with stage 3 NEC compared with 3 of 24 with stages 1 or 2 NEC. Elevated plasma IFABP concentrations were detectable before clinical staging could be made in 5 of the 7 subjects with stage 3 NEC.

CONCLUSION

IFABP may be a specific marker for early identification of severe NEC.

Intestinal mucosal injury in critically ill surgical patients: preliminary observations

This was a prospective study designed to evaluate the extent to which intestinal mucosal compromise occurs in adult critical care patients with and without systemic inflammatory response syndrome (SIRS) and to correlate the degree of intestinal injury with outcome. Ten patients from a university hospital surgical intensive care unit were identified who manifested SIRS at the time of admission to the intensive care unit. Five other critical care patients without SIRS were also evaluated. The Acute Physiology and Chronic Health Evaluation II score was determined. Intestinal mucosal viability was assessed by serial measurement of serum and urine iFABP intestinal fatty acid binding protein (iFABP), a sensitive and specific marker for mucosal injury. Outcome in terms of the development of multiorgan dysfunction syndrome, adult respiratory distress syndrome, and survival was determined. iFABP was detectable in the serum or urine in 8 out of 10 patients with SIRS. Among the 4 patients with detectable serum iFABP, 2 died and 1 developed severe adult respiratory distress syndrome. Nine of 11 patients without detectable serum iFABP recovered without major morbidity. iFABP was detectable in most patients with SIRS, suggesting that subclinical intestinal mucosal compromise is a frequent component of this syndrome. When iFABP was detectable, particularly in the serum, the prognosis was poor, even in the absence of SIRS, indicating that iFABP may be a relevant and independent predictor of outcome in critical care patients.

Organ failure, infection, and the systemic inflammatory response syndrome are associated with elevated levels of urinary intestinal fatty acid binding protein: study of 100 consecutive patients in a surgical intensive care unit

BACKGROUND

Intestinal mucosal ischemia and subsequent barrier dysfunction have been related to the development of organ dysfunction and death in the critically ill. We hypothesized that urine concentrations of intestinal fatty acid binding protein (IFABP), a sensitive marker of intestinal ischemia, might predict the development of the systemic inflammatory response syndrome (SIRS) and organ dysfunction.

METHODS

One hundred consecutive critically ill patients were prospectively studied for the development of infectious complications, organ dysfunction, and SIRS. Urine was collected daily for measurement of IFABP.

RESULTS

A total of 58 males and 42 females (mean age, 56 years; range,16-85 years) were studied. Of these 100 patients, 40 patients developed complications and 5 patients developed SIRS. IFABP was significantly elevated in all patients with SIRS, and IFABP levels peaked an average of 1.4 days (range, 0-7 days) before the diagnosis of SIRS.

CONCLUSION

Elevated concentrations of urine IFABP correlated with the clinical development of SIRS. Studies to assess the utility of IFABP as a predictor of organ dysfunction and SIRS in the critically ill are warranted.

Comparison of quantitative polymerase chain reaction, acid fast bacilli smear, and culture results in patients receiving therapy for pulmonary tuberculosis

Quantitative-competitive polymerase chain reaction (QPCR) was performed on serial sputum samples from 22 consecutive cases of acid fast bacilli (AFB) smear-positive pulmonary tuberculosis. Of 94 specimens, 55, 72, and 83% were positive by culture, AFB smear, and QPCR, respectively. Of 52 culture-positive specimens, 6% were negative by PCR, and 13% were negative by AFB smear. Of 42 culture-negative specimens, AFB smear and QPCR were positive in 55 and 61%, respectively. AFB smear and QPCR results were strongly correlated (r = 0.75, p < 0.001), but each correlated less strongly with culture (r = 0.54, p < 0.005 for smear and r = 0.52, p < 0.005 for QPCR). When patients were classified by microbiologic response, responders tended to have less DNA in their sputum and shorter time to a negative PCR result compared to nonresponders. These data do not suggest a great advantage of QPCR over AFB smear for predicting culture results in patients with pulmonary tuberculosis.

Human intestinal fatty acid binding protein: report of an assay with studies in normal volunteers and intestinal ischemia

BACKGROUND

Human intestinal fatty acid binding protein (hIFABP) is a cytoplasmic protein of mature small intestinal epithelium. Work with the rat demonstrated that serum levels of IFABP correlated with early phases of intestinal mucosal injury. The aim of this study was to develop an assay for hIFABP and assess its usefulness as a marker for intestinal mucosal injury in human beings.

METHODS

Recombinant hIFABP (r-hIFABP) was used to produce rabbit anti-hIFABP. Specificity and avidity of binding were tested with immunoprecipitation and Scatchard analysis. r-hIFABP was labeled with 125I, and a competitive assay was developed. Urine and serum from normal volunteers and from patients with necrotizing enterocolitis (NEC), acute thromboembolic related intestinal ischemia, and systemic inflammatory response syndrome were tested for hIFABP.

RESULTS

Molecular weight was 10(-12) kd, limit of detection was 1.87 ng/ml, and no cross-reactivity occurred when tested against rat IFABP or human heart FABP. Mean levels of hIFABP (ng/ml) were controls (serum less than 1.87, urine less than 1.87), NEC (serum 14.7 ng/ml), intestinal ischemia (serum 50 ng/ml, urine 52.3 ng/ml), systemic inflammatory response syndrome (serum 5.3 ng/ml, urine 13.2 ng/ml).

CONCLUSIONS

This assay is quantitative for hIFABP in serum and urine. Results from both normal persons and those with various causes of intestinal ischemia parallel our previous findings in the rat. Preliminary findings suggest that hIFABP may serve as a diagnostic marker for early intestinal mucosal compromise and, in addition, that it should prove useful as a tool in developing rationale therapeutic regimens to treat these complex clinical problems.

Children hospitalized for varicella: a prevaccine review

OBJECTIVES

To describe varicella complications in healthy and previously ill children hospitalized for varicella and to explore trends in group A beta-hemolytic streptococcus complications of varicella.

METHODS

A retrospective record review of children hospitalized for varicella between January 1, 1990, and March 31, 1994, was conducted in nine large acute care hospitals in Los Angeles County, California.

RESULTS

We identified 574 children hospitalized for varicella in study hospitals during the 4.25-year study period (estimated risk of hospitalization, approximately 1 in 550 cases of varicella); 53% of the children were healthy before the onset of varicella and 47% were previously ill with underlying cancers or other chronic illnesses. Children were hospitalized for treatment of complications (n = 427, 74%) or for prophylactic antiviral therapy or observation (n = 147, 26%). Systems involved in complications included skin/soft tissue (45%), neurologic (18%), respiratory (14%), gastrointestinal (10%), and hematologic, renal, or hepatic (8% or less). The mean age of children with skin/soft tissue infections was 2.7 years (range < 1 to 16 years) compared with 4.7 years (< 1 to 18 years) for other complications. Children with skin/soft tissue and neurologic complications were more often previously healthy (p < 0.05), whereas those with respiratory complications were more often previously ill (p < 0.001). Hospitalizations for skin/soft tissue infections increased during the study period. The proportion of complications as a result of group A beta-hemolytic streptococcus infection increased from 4.7% before 1993 to 12.2% for the remainder of the study period (p = 0.02).

CONCLUSIONS

Prior health status was predictive of the type of complications experienced by children with varicella requiring hospitalization. Our data suggest a recent increase in skin/soft tissue complications of varicella requiring hospitalization and an increase in the proportion of complications related to group A beta-hemolytic streptococcus. Wide-scale vaccine use should reverse this trend and reduce the overall impact of varicella on both healthy and previously ill children.

Acetabular labral tears: evaluation with MR arthrography

PURPOSE

To determine the usefulness of magnetic resonance (MR) arthrography in the diagnosis of acetabular labral tears.

MATERIALS AND METHODS

MR arthrography of the hip was performed in 10 patients who underwent subsequent surgical evaluation. Eight arthrograms were obtained with intraarticular administration of gadolinium solution and two with intraarticular administration of normal saline. T1-weighted spin-echo (intraarticular gadolinium) or T2-weighted gradient-echo (intraarticular normal saline) images were obtained in the axial, sagittal, and coronal planes with use of a surface coil. Criteria for labral tears included labral blunting, absence, displacement, intrasubstance contrast material, and contrast material at the acetabular-labral junction. Labra with enlargement, intrasubstance intermediate signal intensity, or irregular margins were interpreted as degenerative.

RESULTS

Labral tears were diagnosed in eight hips. Tears included six labra with contrast material that tracked at the acetabular-labral junction, one of which had associated intrasubstance extension. One tear was confined to the labral substance. The other tear exhibited absent labral tissue and an irregular remnant. One degenerative labrum and one normal labrum were identified. All MR arthrographic findings were confirmed at surgery. Extension of one anterosuperior tear into the posterosuperior labrum was not prospectively appreciated.

CONCLUSION

In this preliminary study, MR arthrography appears to be a promising imaging modality for accurate diagnosis of acetabular labral tears.

Human syngeneic intestinal transplantation: evaluation of enterocyte viability with serum levels of intestinal fatty acid binding protein

In a case of human syngeneic intestinal transplantation, the post-operative course was complicated by the Systemic Inflammatory Response System (SIRS). This syndrome was characterized by negative cultures and elevated levels of the pro-inflammatory cytokines, IL-1 beta, IL-6 and TNF. In keeping with current concepts of translocation across the enterocyte barrier as the etiology of SIRS, levels of intestinal fatty acid binding protein (I-FABP), an enterocyte-specific protein, also increased. These observations suggest that (i) a clinical syndrome consistent with translocation may occur in the absence of rejection in intestinal transplantation, and (ii) I-FABP may serve as a clinically relevant marker for enterocyte injury.

Safety and immunogenicity of a serogroups A/C Neisseria meningitidis oligosaccharide-protein conjugate vaccine in young children. A randomized controlled trial

OBJECTIVE

To assess the safety and immunogenicity of a bivalent serogroups A/C meningococcal oligosaccharide-protein conjugate vaccine compared with the licensed meningococcal polysaccharide vaccine.

DESIGN

Randomized controlled trial.

STUDY POPULATION

Ninety healthy 18- to 24-month-old children who were seen at a southern California Kaiser Permanente clinic.

INTERVENTIONS

Vaccination with either the meningococcal conjugate vaccine (at 1 of 2 dosages) or the polysaccharide vaccine, with 2 doses given 2 months apart.

MAIN OUTCOME MEASUREMENTS

Immune response to each vaccine dose as determined by measurement of serogroup-specific total antibodies by enzyme-linked immunosorbent assay (ELISA) and by assessment of serum bactericidal activity.

RESULTS

Both vaccines appeared to be safe, and nearly all children responded with greater than 4-fold increases in antibody levels. The 2 dosages of the conjugate vaccine induced similar antibody responses; therefore, the data for the 2 conjugate vaccine groups were combined. Following 2 doses, ELISA antibody levels against group C meningococcus were significantly higher in conjugate vaccine recipients than in polysaccharide vaccine recipients (16.66 microg/mL vs. 8.31 microgm/mL; P<.001), but antibody levels against group A were not significantly different 22.75 microg/mL vs 21.24 microg/mL; P=.70). The serum bactericidal assays showed striking differences between the conjugate and polysaccharide vaccine groups. Geometric mean serum bactericidal titers were significantly higher in conjugate vaccine recipients (755.6 vs 37.6 for group A, P<.001; 3197.9 vs 11.4 for group C, P<.001).

CONCLUSIONS

The immune response induced by this meningococcal oligosaccharide-protein conjugate vaccine was qualitatively different from that induced by the polysaccharide vaccine, and the antibodies it elicited provided greater functional activity.

Disseminated intravascular coagulation associated with rotavirus gastroenteritis: report of two cases

During one winter season, two children with rotavirus gastroenteritis who developed fulminant disseminated intravascular coagulation were seen at our hospital. Disseminated intravascular coagulation probably resulted from hypovolemic shock and acidosis, although extraintestinal spread of the virus cannot be excluded.

Prevalence of bone marrow signal abnormalities observed in the temporomandibular joint using magnetic resonance imaging

PURPOSE

The purpose of this investigation was to determine the prevalence of bone marrow signal abnormalities in patients referred for temporomandibular joint (TMJ) magnetic resonance imaging (MRI). This investigation was done because of prior studies suggesting that condylar marrow signal abnormalities indicate avascular necrosis.

SUBJECTS AND METHODS

Retrospective review was done of 449 consecutive TMJ MR examinations in 415 patients from 1991 to 1994. Examinations were obtained with a surface coil at 1.5 T with routine T1, T2, and T2* images. Condylar marrow signal abnormalities were reviewed and classified into either a bone marrow edema pattern (hypointense T1, hyperintense T2) or a sclerosis pattern (hypointense T1 and hypointense T2). Patients with typical findings of osteoarthritis were excluded from the sclerosis category.

RESULTS

Condylar marrow signal abnormalities were present in 37 patients (9%). Twenty-six patients (6%) had the edema pattern, 14 patients (3%) had the sclerosis pattern, and 3 patients had both. Two patients with the edema pattern had a history of surgery; five patients with the sclerosis pattern had a history of surgery. The only follow-up MRIs obtained in the 37 patients were on one patient with edema at 8 months and on one patient with sclerosis at 10 months. MRI demonstrated a stable appearance of these patterns.

CONCLUSION

It was concluded that condylar marrow signal abnormalities are not rare in patients referred for TMJ MRI. The clinical significance of the changes is uncertain.

The effect of laparotomy and external fixator stabilization on pelvic volume in an unstable pelvic injury

OBJECTIVE

Determine if laparotomy further destabilizes an unstable pelvic injury and increases pelvic volume, and if reduction and stabilization restores pelvic volume and prevents volume changes secondary to laparotomy.

DESIGN

Cadaveric pelvic fracture model.

MATERIALS AND METHODS

Unilateral open-book pelvic ring injuries were created in five fresh cadaveric specimens by directly disrupting the pubic symphysis, left sacroliac joint, and sacrospinous and sacrotuberous ligaments. Pelvic volume was determined using computerized axial tomography for the intact pelvis, disrupted pelvis with both a laparotomy incision opened and closed, and disrupted pelvis stabilized and reduced using an external fixator with the laparotomy incision opened.

MEASUREMENTS AND MAIN RESULTS

The average volume increase in the entire pelvis (from the top of the iliac crests to the bottom of the ischial tuberosities) between a nonstabilized injury with the abdomen closed and then subsequently opened was 15 +/- 5% (423 cc). The average increase in entire pelvic volume between a stabilized and reduced pelvis and nonstabilized pelvis, both with the abdomen open, was 26 +/- 5% (692 cc). The public diastasis increased from 3.9 to 9.3 cm in a nonstabilized pelvis with the abdomen closed and then subsequently opened. Application of a single-pin anterior-frame external fixator reduced the pubic diastasis anatomically and reduced the average entire and true (from the pelvic brim to the ischeal tuberosities) pelvic volumes to within 3 +/- 4 and 8 +/- 6% of the initial volume, respectively.

CONCLUSIONS

We believe that the abdominal wall provides stability to an unstable pelvic ring injury via a tension band effect on the iliac wings. Our results demonstrate that a laparotomy further destabilized an open-book pelvic injury and subsequently increased pelvic volume and pubic diastasis. This could potentially increase blood loss from the pelvic injury and delay the tamponade effect of reduction and stabilization. A single-pin external fixator prevents the destabilizing effect of the laparotomy and effectively reduces pelvic volume. These data support reduction and temporary stabilization of unstable pelvic injuries before or concomitantly with laparotomy.

Effect of neonatal immunization with diphtheria and tetanus toxoids on antibody responses to Haemophilus influenzae type b conjugate vaccines

We randomly assigned 150 newborn infants to receive diphtheria and tetanus toxoids (DT) or Hib oligosaccharide conjugate (HbOC) at birth to determine whether exposure to the Haemophilus influenzae type b (Hib) conjugate vaccines' carrier proteins would enhance immune responses to subsequent administrations of HbOC or PRP-tetanus toxoid conjugate (PRP-T) at 2, 4, and 6 months of age. Their antibody responses were compared with those of 100 children immunized with HbOC or PRP-T beginning at 2 months of age. No serious adverse reactions were associated with neonatal vaccination. Administration of HbOC at birth did not lead to earlier or higher antibody levels. Newborn immunization with DT did not prime children for enhanced antibody responses. Moreover, Hib antibody levels were lower in DT-primed children than in children immunized beginning at 2 months of age. Diphtheria antibody levels, but not tetanus antibody levels, were also lower in children immunized with DT at birth. We conclude that neonatal immunization with Hib conjugate vaccines is not a means to provide earlier protection against invasive Hib disease. Newborn DT administration does not enhance subsequent antibody responses to Hib conjugate vaccines, and may lead to suppression of Hib and diphtheria antibody responses.

Enhanced antibody responses in infants given different sequences of heterogeneous Haemophilus influenzae type b conjugate vaccines

To evaluate the safety and immunogenicity of differing sequences of heterogeneous Haemophilus influenzae type b (Hib) conjugate vaccines, we randomly assigned 300 infants to one of six vaccination schedules. At 2, 4, and 6 months of age, subjects were given single or heterogeneous vaccines: Hib polysaccharide (PRP) conjugated to mutant diphtheria toxin (HbOC), PRP conjugated to outer-membrane protein of Neisseria meningitidis (PRP-OMP), or PRP conjugated to tetanus toxoid (PRP-T). No serious reactions were attributable to immunization with heterogeneous vaccines, and there were few significant differences in the rates of minor adverse reactions among groups. PRP-OMP was the only vaccine that induced an antibody response after the first dose, but significant booster responses were not seen after the second and third doses. Subjects given PRP-T vaccine responded well after two doses, but three doses of HbOC vaccine were needed for an equivalent antibody response. All the Hib vaccine schedules evaluated were immunogenic, and schedules initiated by PRP-OMP vaccine at 2 months of age, followed by two doses of either HbOC or PRP-T vaccine at 4 and 6 months of age, induced the highest antibody levels after each dose. Such schedules may be the best for protecting infants and children who are at greatest risk of having invasive Hib disease, such as American Indian children.

Demonstrating therapeutic interventions for the remediation of symptoms associated with trauma-induced carpal tunnel syndrome: An illustrated case report

An increase of cumulative trauma disorders including carpal tunnel syndrome has been seen in the last 10 years. Common causes of carpal tunnel syndrome include high-risk occupations, pregnancy, diabetes, and trauma. Measures used to diagnose carpal tunnel syndrome are physical examinations, electromyography, computerized tomography, and vibrometers. Carpal tunnel syndrome can be treated through conservative methods, such as splinting and steroid injection, or through surgical procedures. Ergonomic principles can also help to minimize exacerbation of symptoms and possibly prevent carpal tunnel syndrome. A case report is used to describe the long-term effects of trauma-induced carpal tunnel syndrome and to present various therapeutic interventions, including ergonomics, which may be useful in returning clients to work.

Paradoxical enlargement or development of intracranial tuberculomas during therapy: case report and review

Intracranial tuberculomas can sometimes develop or increase in size despite administration of appropriate therapy. We report the case of a child whose intracranial tuberculomas paradoxically enlarged while therapy was being administered, and we review 23 other cases in which tuberculomas increased in size or number and 17 cases in which tuberculomas appeared during therapy. These phenomena generally occurred within 3 months of the start of therapy. All but four patients had neurological deterioration that prompted obtaining a repeated computed tomographic scan. One patient died, about one-fourth of patients had residual neurological symptoms, and less than one-third of the patients required surgical intervention. Most patients received a 12-18 month course of antituberculous therapy. Adjunctive therapy with steroids appears to diminish neurological symptoms and may improve outcome. Paradoxical enlargement or development of tuberculomas usually does not represent failure of antituberculous therapy; the most likely explanation for these phenomena is an interaction between the host's immune response and the direct effects of mycobacterial products.

Rotavirus and other viral causes of gastroenteritis

Diarrheal diseases are a major cause of childhood morbidity and mortality worldwide. Viruses are the leading cause of diarrhea, and rotavirus is the major cause of severe dehydrating diarrhea in both developed and developing countries. Children with viral gastroenteritis generally present with watery non-bloody diarrhea, often with vomiting and low grade fever. Disease is self-limited and treatment is simple--fluid and electrolyte replacement, preferably via the oral route, with early refeeding. While various adjunctive therapies, such as bismuth subsalicylate and oral immunoglobulins, appear promising, they cannot be routinely recommended at this time. Prevention is the key: by good personal hygiene--particularly good handwashing, by maintaining safe water supplies, and in the future, by an effective rotavirus vaccine.

Bacterial resistance in the '90s

The lesson of the antibiotic era is, the microbe always wins. Pediatricians need to understand why, to take the threat seriously, and to mobilize to fight back.

Ultrasound detection of abscesses in the temporomandibular joint following surgical reconstruction

The purpose of this investigation is to report the technique and assess the utility of ultrasound diagnosis of abscess in the postoperative temporomandibular joint (TMJ). Fourteen patients had 18 ultrasound examinations of the postoperative temporomandibular joint (TMJ) to detect a possible abscess. Ultrasound examinations were performed with either a 5-MHz linear array and/or a 7.5-MHz sector probe following placement of implants (16) and autogenous costochondral grafts (2). The TMJ was scanned in both coronal and axial planes. In 14 examinations, an abscess was not detected; there were no false-negatives. Soft-tissue edema was found in 1 of these 14 examinations; at surgery, there was no abscess. Four examinations were positive for an abscess; 3 of these were confirmed at surgery. One examination was false-positive. We conclude that ultrasonography can detect an abscess in the symptomatic postoperative TMJ. A negative examination is reliable.

Evaluation of tibial plateau fractures: efficacy of MR imaging compared with CT

OBJECTIVE

CT is often used after plain films to evaluate fractures of the tibial plateau. Because MR imaging can show associated soft-tissue injuries as well as fractures, we hypothesize that MR is superior to CT for imaging these injuries. Accordingly, we compared the efficacy of MR imaging and CT in 22 patients with tibial plateau fractures.

SUBJECTS AND METHODS

CT with two-dimensional reconstruction and MR examinations were performed in 22 patients with tibial plateau fractures. The images were interpreted by four radiologists and two orthopedic surgeons. Findings on CT scans and plain films were used to determine the configuration of the fractures and to classify them according to the Schatzker system. This was done with findings on MR images and plain films at a separate session. The MR images were also evaluated for ligamentous and meniscal injuries. A qualitative side-by-side comparison of two-dimensional CT scans and MR images for depiction of fracture configuration was done. Imaging results were correlated with observations from physical examinations in all patients and with surgical findings in 12 patients.

RESULTS

All of the six types of fractures of the Schatzker classification were observed in this series. Comparison of two-dimensional CT reconstructions and MR images for depiction of fracture configuration revealed that the two techniques were equal in 14 patients, MR imaging was superior to CT in five patients, and CT was superior to MR imaging in three patients (who had very complex and comminuted fractures). In addition, MR imaging showed 12 complete ligamentous tears and 15 partial ligamentous tears in 15 (68%) of the 22 patients. MR showed meniscal injuries in 12 (55%) of the 22 patients.

CONCLUSION

MR imaging was equivalent or superior to two-dimensional CT reconstruction for depiction of fracture configuration in most patients. In addition, MR showed significant soft-tissue injuries. We believe that MR imaging is the preferable imaging technique for most patients with fractures of the tibial plateau.

Gastrointestinal radiology: current indications and referral patterns

To determine the current indications and referral patterns for routine gastrointestinal radiology examinations, 1000 consecutive patients were prospectively analyzed. The following specialties were the largest sources of referral: general internal medicine (38%), gastroenterology (21%), and general and colorectal surgery (17%). Referrals from gastroenterologists were weighted toward areas not well evaluated by endoscopy, such as suspected small bowel disease. The major indications for upper gastrointestinal (GI) examinations were dysphagia and swallowing disorders (32%), hiatus hernia/reflux (14%), and ulcer (14%). Small bowel series were predominantly performed for inflammatory bowel disease (37%), obstruction (25%), and occult blood loss (18%). The majority of combined upper GI/small bowel studies were performed for indications primarily relating to the small bowel. Forty percent of barium enemas were performed for detection of neoplasms and polyps, with pain/irritable colon (14%) and exclusion of leak (14%) the next most common indications. Traditional indications, such as peptic ulcer disease and neoplastic disease, continue to be sources of referral for gastrointestinal radiology. However, more specialized applications, particularly in areas not well suited to endoscopy, such as swallowing disorders, inflammatory disease of the small bowel, and evaluation of surgical anastomoses, are also being commonly used. The changing indications, along with the previously documented decreased volume of gastrointestinal radiologic procedures, should be kept in mind when planning a radiology resident educational curriculum.

MR imaging of the juvenile temporomandibular joint: preliminary report

Thirty-two children were evaluated by means of medical history and physical examination for signs and symptoms of internal derangement (ID) of the temporomandibular joint (TMJ) and mandibular dysfunction. These children also underwent magnetic resonance (MR) imaging of the TMJs. The study was double blind. At clinical examination, 19 patients (59%) had at least one positive finding of ID of the TMJ and/or mandibular dysfunction. MR images of the TMJ obtained in 60 of the 64 TMJs demonstrated 57 normal joints (95%) and three abnormal joints (5%). Two of these three joints had a mild anterior-lateral disk displacement, and one joint had an anterior dislocated disk. There were no false-positive MR examinations. MR imaging failed to depict abnormalities in 16 patients who had positive findings at history and/or physical examination. Although MR imaging may fail to depict ID of the TMJ in some patients, clinical techniques commonly used in population surveys probably overstate the prevalence of ID of the TMJ in children.

Prevention of bacterial meningitis. Vaccines and chemoprophylaxis

The morbidity and mortality caused by bacterial meningitis remains significant despite advances in antimicrobial therapy and supportive care. Prevention of meningitis by routine immunization of infants, who are at greatest risk, offers the only practical way of reducing the incidence of this disease. Widespread use of the recently developed protein conjugate vaccines against Haemophilus influenzae type b by itself could reduce the incidence of bacterial meningitis in the U.S. by more than half. To prevent disease caused by the other pathogens, an effective vaccine against the group B meningococcus must be developed, and the immunogenicity of the pneumococcal and quadrivalent meningococcal vaccines should be improved. Until such time that universal immunization of infants with highly immunogenic vaccines is possible, continued efforts must focus on targeting immunization at high-risk individuals and using chemoprophylaxis to prevent secondary disease where indicated. Addendum: On October 4, 1990, the U.S. Food and Drug Administration licensed the praxis Haemophilus influenzae type b-protein conjugate vaccine (Hboc) for use in infants at 2, 4, and 6 months of age with a booster dose at 15-18 months. Physicians are directed to statements by the Immunizations Practices Advisory Committee and the American Academy of Pediatrics for official recommendations concerning its use.

Dermal grafts of the temporomandibular joint: postoperative appearance on MR images

Complications may follow meniscectomy and placement of an allogenic implant in temporomandibular joint (TMJ) dysfunction. To characterize the anatomy of autogenous dermal grafts for repair and repositioning of the meniscus, the authors performed T1-weighted magnetic resonance (MR) imaging of 20 TMJs in 10 patients 6-23 months after surgery that was considered successful. MR imaging did not enable detection of the dermal grafts. Comparison of preoperative and postoperative MR images revealed little, if any, change in meniscal position. MR images of 20 menisci revealed anterior displacement (n = 11), normal position (n = 4), focal areas of increased signal intensity (n = 4), fragmentation (n = 2), and suboptimal visualization (n = 5). MR images of 20 condyles revealed normal features (n = 11), erosions (n = 2), early avascular necrosis (AVN) or subchondral cysts (n = 2), AVN (n = 3), an osteophyte (n = 1), and loss of bone (n = 2). One TMJ demonstrated increased soft tissue in the bilaminar zone.

Use of three-dimensional computerized tomography in the diagnosis of an obstructed coronoid process

The principles of three-dimensional computerized tomography are discussed. An unusual case of an iatrogenically induced coronoid obstruction is presented with the three-dimensional computerized tomograph as an integral tool in its diagnosis.

Magnetic resonance imaging of ruptured Baker's cyst

The clinical presentation of a ruptured Baker's cyst and of thrombophlebitis can be identical. Venography, arthrography, and more recently ultrasonography have been used to differentiate these two entities. We report a patient with a ruptured Baker's cyst who was also evaluated using magnetic resonance imaging (MRI). The soft-tissue abnormalities were better demonstrated by MRI than by the other imaging methods.

Juvenile rheumatoid arthritis: assessment with MR imaging

Thirty-three joints of the appendicular skeleton in 15 children with juvenile rheumatoid arthritis were examined with magnetic resonance (MR) imaging to determine if it could demonstrate synovial hypertrophy and status of the articular cartilage. Presumed synovial hypertrophy was seen in 13 joints as masses of varying sizes of low to intermediate signal intensity on T1- and T2-weighted images; sometimes foci of increased signal intensity, most likely due to fluid or inflammation, were seen on T2-weighted images. Probable abnormal articular cartilage was detected in ten joints, and MR imaging also demonstrated epiphyseal overgrowth, bone erosions, joint effusions, and joint space narrowing. Because MR imaging appears to provide an objective method of evaluating both synovial hypertrophy and status of articular cartilage, it may prove to be useful in monitoring progression of juvenile rheumatoid arthritis and response to therapy.

Hemophilic arthropathy: assessment with MR imaging

Fifteen patients with hemophilia, 14 of whom had hemophilic arthropathy, were examined with magnetic resonance (MR) imaging to determine if it could be used to assess hemophilic arthropathy, especially synovial hypertrophy and the status of the articular cartilage. Thirty-five joints of the appendicular skeleton were imaged. Four joints in two patients were clinically normal. Synovial hypertrophy was detected in 28 joints and appeared as areas of low to intermediate signal intensity on T1- and T2-weighted images, with foci of increased signal intensity on T2-weighted images (presumed to be due to areas of fluid or inflammation) in 16 joints. Abnormal articular cartilage was demonstrated in 26 joints; bone lesions, fluid collections, and joint space narrowing could also be seen. MR imaging appears to be useful in depicting the components of hemophilic arthropathy.

Magnetic resonance imaging of the heart

Magnetic resonance (MR) has noninvasively imaged the proximal coronary arteries, areas of infarction, and a variety of congenital heart lesions. Further technical improvement may extend cardiac MR from the realm of research to clinical utility.

Gated magnetic resonance imaging of the normal and diseased heart

Gated cardiac magnetic resonance (MR) images were obtained in two normal volunteers and 21 adults with a variety of cardiovascular abnormalities. The images were correlated with data from clinical examinations, electrocardiograms, and cardiac catheterization. Gated cardiac images were superior to nongated images. Combined cardiac and respiratory gated images were superior to images obtained with cardiac gating only, but acquisition time was longer. Portions of the coronary arteries were visualized in seven of 23 examinations (30%), and subacute and old myocardial infarcts were seen in five of nine patients (55%) as areas of thinned myocardium. No signal changes were observed in the patients with subacute infarctions or the patient with myocarditis. Coronary atherosclerotic lesions were not visualized in any of the patients. Normal cardiac anatomy (chambers, valves, and papillary muscles) was well visualized. Examples of aortic stenosis and atherosclerosis of the abdominal aorta are shown.

Computed tomography of diverticulitis

Computed tomography (CT) is capable of imaging diverticulitis of the colon. Localized wall thickening, soft tissue density in the pericolic fat, and large soft tissue masses that may or may not contain gas have been observed in diverticulitis. Because of its noninvasive nature, CT may have an advantage in the acute phase of diverticulitis when there may be reluctance to do a barium enema. More experience will be needed to see if CT will be predictive of a need for surgery.

Preliminary experimental results in humans and animals with a superconducting, whole-body, nuclear magnetic resonance scanner

In order to determine the clinical usefulness of nuclear magnetic resonance (NMR) imaging, the investigators examined a variety of normal volunteers, patients with neoplastic lesions, and experimental animals. Preliminary results were obtained with the use of potential contrast agents. It was found that imaging applications of NMR in the vascular system, spine, brain, lung, and mediastinum offer certain advantages over other modalities. The absence of biological hazard as well as the ability to obtain unenhanced, noninvasive, gated images of the vascular system, as demonstrated in this study, make NMR particularly attractive. In addition to single-section capability, NMR makes it possible to obtain volume images of the spine and other organs which can be displayed in any desired plane or section thickness.